My Demoness [MHA Various x KNY!Reader]

S3 E1

"My Quirk deals with weapons... My Quirk deals with weapons..." (Y/n) mumbled to herself as she swung her sword. "Focuz on training, not your lie" Kokoshibo scolded as he observed her. "I know... My real Quirk is practically useless, being able to smell anything, even emotions" (Y/n) grumbled as she pouted.

Her phone buzzed in her pants, interrupting her training session with her brother. "Hm? Oh, I just got a text from my classmates. Looks like they want to meet up at the pool" (Y/n) informed as she showed her brother. "I suppose you have to keep up appearances, to get close to them. I'll inform Muzan, don't spend long there" Kokoshibo lectured as he patted her head.

"Thanks, Oniisan! Nakime-ane~ Can you send me to the school please?" (Y/n) called out. On cue, a Shoji door appeared under her, and she fell through and was transported to her desired destination. "Thanks, Oneesan" (Y/n) said gratefully as she picked up the bag and made her way to the school.

She was genuinely happy that she gets some time off from training, maybe next time she can sneak in her best friends, Inasa, and Toga. Once she got to the school, she had the misfortune of seeing everyone from her class there. Thankfully, the school provided her with swimsuits. She shrugged, not really caring, as long as she gets time off from training.

"Heads up!!" (Y/n) warned as she tossed the ball into the air, heading nowhere in particular. "I've got it!!" Mina exclaimed as she scrambled to hit it. "Ribbit!" Asui croaked as Mina passed it over to her, as she easily hit it with her tongue. The girls chuckle as they passed the ball around in circles, allowing everyone to attempt hitting it.

In the distance, they can see the guys working their asses off to train, taking laps around the pool. Though they had limited space, thanks to the girls using half of it. "Hey! Everyone! I propose a friendly race between us guys! We swim 50 meters the fastest" Tenya proposed, catching the girl's attention.

"Iida, why don't you let us help you out?" Momo asked as they all got out of the pool. "Oh, hey, when did you get here, Bakugo?" (Y/n) asked as she approached the blond. "Just a few minutes ago, I couldn't miss out on beating everyone's asses!" Katsuki cackled, earning a sweatdrop from Kirishima. "I convinced him to come along, told him that you were here" Kirishima admitted sheepishly.

Izuku froze at the comment, he didn't expect Katsuki to actually enjoy (Y/n)'s presence. "I'm going to annihilate you, Deku!" Katsuki claimed as he glared at his old friend. "I wish you luck, Kirishima" (Y/n) said as she patted her friend's shoulder. "Thanks... I'll definitely need it" Kirishima mumbled with a nervous smile.

In no time, the first round started, and (Y/n) held the whistle, while the other girls observed. "Alright, everyone ready? On your marks. Get set..." (Y/n) trailed off before blowing into the whistle. "Eath Speed Turbo!!" Katsuki yelled as he flew through the air, while his opponents swam. "How was that, you side dicks!" Katsuki exclaimed as he pointed at them.

"What do you think you're doing?!" Sero screeched as he glared at Katsuki. "You didn't even touch the water!!" Kirishima pointed out, also glaring at Katsuki. "It's called free-style swimming!!" Katsuki yelled back, as he sparked his palms. No one else made complaints as the next group was up.

"On your marks. Get set..." (Y/n) blew into the whistle allowing them to start. This time, most of the group tried Katsuki's tactic, but only Shoto's Quirk got him across. "You're supposed to be swimming!!" Kaminari and Mineta exclaimed once Shoto finished the race.

"Last group! On your marks! Get set!" With another whistle blown, the group set off. (Y/n) was a bit surprised that Tenya used his quirk on the pool lines. She would've thought he'd find that cheating, she supposes that if he's doing it then it's fine. Of course, Izuku had to use his quirk in the water, and easily caught up to Tenya. The audience cheered as Izuku got to the finish first, with Tenya only inches away from winning.

"It's time for the final race, Bakugo, Todoroki, Midoriya, as winners of each team, you'll fight for first place, understand?" Tenya asked as he looked at the boys. "Got it!/Yes..." Izuku and Shoto answered casually, despite their difference in tone. "Listen, scar face, don't you dare hold back on me. Bring everything you've got!" Katsuki exclaimed.

(Y/n) sweat dropped as she held the whistle in her hand. "It's just a fun swimming contest... Why are they getting so serious?" She mumbled to herself. Eventually, the three got in their positions, and when (Y/n) blew the whistle the race commenced. Before they could even get past the start, they all fell awkwardly into the water.

"It's 5 pm, and your authorized pool time is officially over, hurry up and go home" Aizawa grumbled as he walked over to them. "Come on, just one second!" Kaminari complained unhappily. "We're finally getting to the good part" Sero added as he pointed at the pool. "Are you questioning me?" Aizawa threatened as he glared at the two.

"Damn it! I can't believe he stopped the race like that!" Katsuki yelled as he kicked a rock. "Don't take it to heart, he's only doing his job" (Y/n) reassured as she walked next to him. "Yeah, what she said, just cool your blasters, man. Plus, those two aren't just your opponents, they're our friends" Kirishima pipped in.

"Would you both shut up? I don't care if they're my classmates or not. I won't let them get ahead of me" Katsuki growled. "Whatever you say... I'll see you two later, I have to get home before my father gets mad" (Y/n) said as she started to walk away from them. "Don't slack off! Or else I'll kill you!" Katsuki yelled at her earning a nervous chuckle from Kirishima.